[ticket/12957] Update the constructions of the template engine

PHPBB3-12957

phpBB/phpbb/template/twig/environment.php

@@ -79,6 +79,7 @@ class environment extends \Twig_Environment
 		if (null === $this->lexer)
 		{
 			$this->lexer = $this->container->get('template.twig.lexer');
+			$this->lexer->set_environment($this);
 		}
 
 		return $this->lexer;

phpBB/phpbb/template/twig/lexer.php

@@ -15,6 +15,11 @@ namespace phpbb\template\twig;
 
 class lexer extends \Twig_Lexer
 {
+	public function set_environment(\Twig_Environment $env)
+	{
+		$this->env = $env;
+	}
+
 	public function tokenize($code, $filename = null)
 	{
 		// Our phpBB tags